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From: TELECOM Moderator
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Subject: Autovon: The DoD Phone Company
Status: R
>From telecom Fri Oct 30 00:16:42 1992
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From: TELECOM Moderator
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To: telecom
Subject: Autovon: The DoD Phone Company
Status: R
Here is a submission received recently which was too large for
inclusion in a regular issue of the Digest. It is being filed in the
Telecom Archives for further reference also.
PAT
Date: Thu, 29 Oct 92 18:24:43 EDT
From: Tom Coradeschi
Subject: Autovon: The DoD Phone Company
Organization: Electric Armts Div, US Army ARDEC, Picatinny Arsenal, NJ
From: CHIPS_EDITOR@nctamslant.navy.mil (NARDAC NORFOLK)
Newsgroups: dod.general
Subject: CHIPS ON-LINE OCT 92
Date: 19 Oct 92 15:00:00 GMT
Autovon: The DoD Phone Company
By Peter B. Mersky
Editor's Note: An article on the DoD phone company in Chips? I'm sure
some computer purists are scratching their heads and wondering if I've
lost mine. However, when Alexander Graham Bell said, "Come here,
Watson. I need you." What he meant was, "Hook up your modem and dial
my BBS." Obviously, hoping Watson could get a clear circuit. Corny?
You're right -- now that I have your attention ...
Anyone who has served in the military or who has worked in a DoD
office since the early 1960s has had experiences with the military's
long-distance phone system, universally called Autovon. Usually, these
encounters involve frustration, long connection waits, frequent
cutoffs (referred to as being preempted) and occasionally poor
reception. The only saving grace of the Autovon system was that it was
free. Right? Well, not really.
Autovon's notoriety grew as its coverage expanded. But, just where did
Autovon come from? I wasn't surprised that nobody has ever researched
Autovon's history. It's like writing about the Q-tip. We take such a
mundane, everyday tool for granted and never think about its heritage
or development. There's very little specific recorded history on
Autovon's birth. The story is part of a corporate memory, currently
residing with members of the Defense Information Systems Agency
(DISA), formerly the Defense Communications Agency. DISA manages DoD's
primary communications worldwide.
Autovon had its beginnings with the Army's Switch Communications
Automatic Network (SCAN), a three-switch system developed for their
own use. (A switch is a basic unit of an overall network and is
usually an individual telephone system.) At this time, each service
strung up its own private networks according to requirements.
Logistics bases would work circuits between themselves. Quartermaster
sections had circuits to their counterparts throughout the country.
Sometimes, one service would let another service use a few of its
circuits to call a base, if the sister service had an ongoing need.
At the height of the Cold War, DoD began looking for a common-user,
long- distance telephone system that would survive enemy attack and
still give command and control capabilities to appropriate levels of
the government and the military. DoD selected the Army's SCAN as the
basis for a worldwide communications link, eventually listing SCAN as
a DoD resource in 1963 and renaming it the Automatic Voice Network
(Autovon). By the mid 1970s, Autovon had been deployed in the European
and Pacific theaters.
Jim Sage, Chief of DISA's Voice Network Operations Directorate,
likened Autovon's structure to the public phone system. In your system
at home, you dial 1, then a ten-digit number. You actually dial into a
local system which then switches you into a long-distance network,
passing your call along until it reaches its destination.
"We did essentially the same thing with Autovon. Post-camp stations
had a small system that served all the users on the installation. If
you want to call downtown, dial 9, then the number. If you want to
call long distance, your local phone system can be connected to the
DoD long-distance system, Autovon, by various methods. This is the
Autovon long-distance network; it doesn't give you local service. It
can be compared roughly to AT&T, MCI or SPRINT long-distance telephone
networks."
Autovon had some features that public service telephones lacked. Above
all, it was a military communications network. The Joint Chiefs wanted
their command and control capability in a crisis or war. They wanted
their phone system to be able to survive enemy attack -- even if its
human users didn't -- so they buried some of the Autovon switches
underground.
To further ensure survivability, the system was so interconnected that
the loss of a few switches wouldn't affect the overall network.
Robustness was the watchword. Another feature of Autovon was
multi-level precedence preemption (MLPP). There are various degrees of
importance regarding military phone calls: flash override, flash,
immediate, priority and routine. People who might be calling from one
finance center to another to check on a serviceman's pay record would
be classified as routine users. However, someone directing troop
movements or high-level security matters where decisions must get
through, has flash override capability. When Autovon is saturated with
calls, if the supporting trunklines are tied up, selected users with
higher precedence will get their calls through by using MLPP.
As the far-ranging Autovon network grew, it became obvious that its
ancient analog technology was out of date. Digital technology had made
tremendous strides, and DoD wanted to incorporate these advances into
its long-distance phone system. By the mid-1970s, planning was
underway to replace Autovon. The new system was called the Defense
Switched Network (DSN). The replacement cost was high, and the move to
DSN couldn't occur overnight. There were many switches involved in
building and deploying DSN, while phasing Autovon out and maintaining
operational standards. DSN deployment continued through the early
1980s, mainly in the European and Pacific theaters. However, the
archaic Autovon was growing old and more difficult to maintain in
CONUS.
The solution was what Jim Sage called "a technological shot in the
arm." The Defense Commercial Telecommunications Network (DCTN)
included some of DSN's advances as well as the new capability of
video-teleconferencing. DCTN interconnected with Autovon via a variety
of circuit arrangements, including one- and two-way links. DISA
expanded DCTN throughout the late 1980s. AT&T, the prime contractor
for DCTN, as well as the original Autovon system, agreed to take out
many of the old analog switches and replace them with new No. 5
Electronic Switching Systems at no cost to the government. DISA could
also take out more switches and further reduce the communication
system's cost. From 1988 to 1991, DISA claims to have saved $49
million in modernizing the Autovon-DSN-DCTN system.
A common misconception is that DSN service allows free long-distance
calls. In fact, DoD's overall annual budget for long-distance
communication is $289 million worldwide. This amount doesn't reflect
the fact that much of the hardware is already bought and paid for.
Much of the money goes toward financing the cost for individual
post/camp/station access and backbone trunking.
When a user in Norfolk calls another office, say in California, the
cost of that call is part of the overall budget and expense of
communications. Household phone consumers pay two rates for their
services: a flat rate for local service and a call-by-call rate for
long distance service. The military setup is basically the same, with
a little variation. DoD offices pay a flat rate for the local lines --
the numbers you call by first dialing 9 -- and a user fee for DSN
lines. However, the Navy, and the rest of the military, tailors its
individual phone service to the local budget and requirements of the
particular military base. Using a shopping list supplied by DISA, a
particular base may select two or three overseas lines, ten
transcontinental hookups and a similar number of local lines. Each of
the hookups is charged at a particular rate and makes up that office's
annual communications budget. Thus, each military installation has a
specific number of DSN lines based on the available funds in its
budget.
DISA uses a "P" (for percentage) factor to describe the success or
failure rate of connections on DSN. Usually, the desired rate is P-10.
That is, for every 100 calls within a geographic area (referred to as
a theater), 10 are blocked. Considering how many DSN calls are being
made at any one time, it's easy to see why we have so many failures,
one of the most frustrating and time-consuming aspects of DSN. P-10 is
included in the linkage between the originator and destination. For
instance you want to call California from your office in Virginia,
there may be only 10 DSN lines available from your base, which block
three out of every 100 calls. After getting onto one of those 10 local
DSN lines, you must now get across the backbone network, which will
block four out of every 100 calls, to the funnel of, perhaps, another
10 lines, at your destination, which, in turn, will block three out of
every 100 calls. At any stage along the road, your call could fail to
complete. Adding up the numbers of blocked calls (3+4+3), you arrive
at the P-10 factor.
To further confuse things, some areas may enjoy a P-0! In November
1991, Norfolk had an overall P-47 rating for DSN access. However,
during the same timeframe, NAS Alameda was rated at P-0, no trouble
getting onto the DSN. In some cases, a rating of P-60 is not uncommon.
The current top five high-blocking DCTN (Navy) Access Areas are NAS
Moffett Field, NAVSTA San Diego, NAS Lemoore, MCAS El Toro and NAS
Oceana. The P- factors for these areas range from 48 to 65. Funding
will probably not allow the necessary increase in circuits to relieve
the congestion.
OK, so that may explain some of the difficulty in using DSN, but what
about the cost? Again, the military pays a flat rate for DSN service.
Thus, the more you use DSN, the cheaper each call is. If your base
pays $1,000 a month for a DSN line, and you make only two calls, then
each call is $500! Hardly economical. But, if you make 1,000 calls on
the same circuit each month, the individual cost is only $1.
What about using commercial service when the DSN is uncooperative?
While it might not seem at first that substituting commercial calls
for DSN is wasteful, particularly on routine matters, it is. Consider
the office worker in Norfolk who decides to check on his buddy in
California, just a short five-minute DSN call to see how he's doing.
It's not uncommon for every one of the DSN circuits of a particular
base to be busy. But, perhaps one is open at the time the yeoman
places his call to his friend. At the same moment, another worker in
another office has official business to negotiate. He picks up the
phone, but the vacant line is now carrying the yeoman's personal call.
The second worker can't get through. He dials repeatedly, his
frustration and sense of urgency rising with each rapid busy signal.
Finally, he gets permission from his boss to use commercial service.
Now, that $10 commercial call, probably made at the top mid-day rate,
becomes an added expense that might have been saved. Of course, the
usual reaction is that commercial calls are figured into the operating
budget, right along with DSN service. True, but in these times of
drastic budget cuts, it is well to consider how commercial calls can
eat so far into the budget that there may come a time where the base
commander tells his office heads, "Hey! I don't have any money for
outside long-distance calls. Tell your folks to use DSN."
Even with purely official calls, the DSN system is periodically
saturated. Each November, AT&T notes a huge increase in the number of
calls coming into the Arlington area. All over the world, sailors know
that this is the time when the advancement test scores are released.
Detailers and counselors are deluged with frantic inquiries about the
caller's success or failure in making E-5 or E-6. (For the Air Force,
this busy time is in August, and the place is Texas.) In some
respects, the military, beset with budgetary crunches and operational
concerns, isn't worried about easing the plight of the harried DSN
consumer. Remember, the system was always intended as a command and
control network for high level government and DoD officials. Its use
as a daily communications service for office workers was secondary.
Jim Sage talked about discussions between DISA and DoD. "We try to
lean on the military users. We tell them, 'Look, your circuits are
overloaded, and your people are angry.' We argue with them a lot. But
the real story is simple: DoD is saying that they only have so much
money. 'DISA,' they say, 'you may be 100 percent right, but not only
do we not have the money, but the money we thought we had has been cut
again.' "
"When the Navy in Norfolk says it can't afford the same services any
more, we ask, 'Well, what can you afford?' We try to tailor the
service, but usually end up taking out some of the circuits or
services. And it's going to get worse. In DoD's defense, they're
getting the best bang for their buck. When the DSN lines are saturated
during a busy day, they're getting their money's worth. And if a
crisis arises, those authorized precedence will be able to get through
by pre-empting calls of lesser importance."
Will the service get better? What are the problems now? As in other
areas of current military concern, economics play a large part in
defining DSN in the 1990s and beyond. DISA monitors traffic along its
existing lines, much like those people on the side of a busy
thoroughfare who count cars during the rush hour. An internal program
monitors DSN switches, samples call flow and tells system engineers
what's happening. If the number of calls rises dramatically in a
particular area, DISA adds more trunk lines, although not immediately.
Outside the metropolitan Washington area, near Leesburg, Virginia, in
the small town called Dranesville, AT&T maintains a modern network
control center dedicated to monitoring CONUS DSN operations. One of
the minor phenomena of Autovon and DSN is the so called high and dry
connections. This abortive call occurs when, after getting on the DSN,
and dialing your destination, the connection is completed but all you
hear is ... nothing, dead air.
People usually hang up and try again. Eventually, they manage to
complete their connection. What they don't realize is that the bad
connection -- in reality, the bad circuit, much like a floppy disk's
bad sector -- is still there. Someone else will encounter it; maybe
even the original caller if the system is busy enough. DISA strongly
recommends that consumers call the Dranesville control center and
report a bad connection. The DSN number to Dranesville is 550-1611.
While DISA and DoD have realized substantial savings in the last 15
years -- $94 million, in fact -- that money doesn't go back into the
DoD phone system. A JCS recent study revealed that with an extra
annual $10 million, DISA could offer every CONUS military base a
P-capability. But DoD has other places to spend that money.
As we head toward the turn of the century, DSN will continue evolving
into the planned integrated network its designers envisioned. Voice
and data services will combine into one network for local and
long-haul transmissions, called the Integrated Services Digital
Network (ISDN).
Acknowledgements: I would like to thank Mr. Jim Sage; LTC Stephen
Kubiak, USA; LT Carlene Wilson, USN; and Ms. Beverly Sampson of DISA;
and CDR John Howard and Mr. Ron Olson of NCTC's Network Validation
Department for their help.
About the Author: Mersky is the assistant editor of Approach, the
Naval Aviation Safety Review. He has written or coauthored several
books on Navy and Marine Corps aviation. Mersky is a commander in the
Naval Reserve. He can be reached at Commercial (804) 444-7758 or DSN
564-7758.
-----------------------------
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